[potatolicious]

> "Why would a computer/website be polite to me?"

The computer isn't being polite to you, the company whose website you are on, is. In the same way your computer isn't being casual and friendly with you - the person who wrote you the email is.

Whether it's an app or a website, it's all just a conduit - and I don't think it's farfetched to say that by and large companies use polite forms when referring to their (potential) customers.